Samsung launched exactly the same type of drive earlier this year, though they have yet to turn up in laptops in any volume. Seagate says its drives are available from this week, and has named the Sony Vaio SZ650 as one model in which the drive will feature for interested buyers.

The company said that the Vaio SZ650 showed 25 percent battery life improvement over the same system without the PSD drive, as well as more rapid boot and de-hibernation times. The PSD was also expected to add around 25-30 percent to the price of such a system, which means hybrid hard drives will for some time turn up mostly in premium ‘road warrior’ laptops where battery life is rated as important.

Other benefits of the new drive included better shock resistance, now set at 900Gs, the ability to spin down to reduce system noise, and higher mean time between failure (MTBF) figures. The drive ships with a five year warranty.

Seagate product marketing manager Melissa Johnson was keen to talk down rival technologies such as SSDs (solid state drives), which she said were going to be too high in price and low in capacity to present a realistic migration path for laptop makers and users.

“Reliability is a question,” she said. “They [SSDs] are an unproven entity,” she said.

SSDs have been sold in a small number of Sony and Dell laptops, but these were all at the very top of the price curve.

Vista users will welcome the lower boot times, something that has turned out to be one of the operating system’s weaknesses, and likewise power drain, another Vista black spot. Does lower power drain make the Momentus PSD a green drive as Seagate would like to claim? Not necessarily.

Welcome as it is, it might simply take Vista users back to the battery life levels enjoyed by the less power-hungry XP.